Intuitive mobile device interface to virtual spaces

ABSTRACT

The present invention relates to a simple to use intuitive interface for mobile devices and, in particular, to a method and apparatus to permit the motion of a mobile device to serve as an input to the mobile device. In various embodiments, the relative and/or absolute motion, distance and/or acceleration for instance, of the mobile device may be mapped to correspond to particular commands. In one embodiment, this permits the display screen of the mobile device to serve as a virtual window to view a large data set by modifying the view of the displayed data according to the motion of the mobile device. In another embodiment, the present invention allows the user to navigate a virtual space, displayed on the screen of the mobile device, by the motion of the mobile device in real space. Additionally, the user may also control the different displayed views of virtual objects by the relative and/or absolute motion of the mobile device.

FIELD

[0001] The present invention relates generally to an intuitive mobiledevice interface and more particularly to a method and apparatus toenable the relative and/or absolute motion of a mobile device to serveas a one-dimensional or multidimensional input to the mobile device.

BACKGROUND OF THE INVENTION

[0002] As the demand for information and connectivity has grown, mobilecomputing devices have been increasingly deployed to provide convenientaccess to information. The term mobile computing devices, or mobiledevices, as used herein, includes mobile phones, beepers, hand heldcomputers and/or devices, personal digital assistants, and any othertype of mobile user electronic device with a display area of some form.

[0003] The small size and lightweight of mobile computing devices givesthe user a sense of intimacy and control. However, these same advantagesrequire that the screen size of mobile devices be small so that they canbe hand held. This leads to cumbersome user input interfaces sinceconventional interfaces, such as keyboards and mouse devices, usuallyhinder mobility.

[0004] Typically, users are limited to using touch screens, stencils, orbuttons as input interfaces to mobile devices. Such input interfaces arecumbersome requiring the use of both hands, one to hold the mobiledevice and the other to enter data.

[0005] Another difficulty with the small display screens of mobiledevices is controlling the view and/or movement of representations ofdata and/or objects, also referred to as the virtual space. Indicatingthe desired movement in the virtual space may be cumbersome and slowusing a stylus or touch screen. For example, indicating the desiredmotion in a three-dimensional virtual space may be awkward usingtwo-dimensional interfaces such as stylus or touch screens. Moreover,controlling movement in a virtual space by using a stylus or touchscreen may conflict with other modes of operation of the inputinterface.

[0006] The small screen sizes and cumbersome interfaces limit thedisplay of larger data sets. Some of these data sets may includetwo-dimensional data, such as text, three-dimensional data, such visualobjects, or four-dimensional data, such as visual objects that changeover time. The user may be limited to viewing small documents or objectsor small parts of a large document or objects.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1A shows a sample of a two-dimensional data file.

[0008]FIG. 1B illustrates a first view of the two-dimensional data filein FIG. 1A as seen on a small screen of a computing device of thepresent invention with the device at a first position.

[0009]FIG. 1C illustrates a second view of the two-dimensional data filein FIG. 1A as seen on a small screen of a computing device of thepresent physically moved the device to a second position.

[0010]FIG. 1D illustrates a third view of the two-dimensional data filein FIG. 1A as seen on a small screen of a computing device of thepresent invention having physically moved the device to a thirdposition.

[0011]FIG. 1E illustrates a third view of the two-dimensional data filein FIG. 1A as seen on a small screen of a computing device withoutchanging the size of the data displayed.

[0012]FIG. 2 illustrates how, in one embodiment of the presentinvention, rotation of a mobile device about a substantially horizontalaxis may result in left or right scrolling of the data displayed.

[0013]FIG. 3 illustrates how, in one embodiment of the presentinvention, rotation of a mobile device about a substantially verticalaxis may result in upward or downward scrolling of the data displayed.

[0014]FIG. 4 illustrates the operation of one embodiment of the presentinvention showing how moving a mobile device in multi-dimensional spacecauses a different view of a virtual object to be displayed on thescreen.

[0015]FIG. 5 illustrates how, in one embodiment of the presentinvention, moving a mobile device towards, or away from, the user causesan zoomed-in, or zoomed-out, view of a virtual object to be displayed onthe screen of the mobile device.

[0016]FIG. 6 illustrates one way of detecting the motion of a mobiledevice by means of an external camera to distinguish the mobile device'sposition and/or orientation.

[0017]FIG. 7 illustrates one way of detecting the motion and/or positionof a mobile device by means of a camera on the mobile device torecognize a plurality of external reference points.

DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention provides an intuitive motion-based and/orposition-based interface to provide a one-dimensional and/ormulti-dimensional form of input. In one application, the presentinvention enables displaying large data sets on a small screen by usingthe screen as a virtual window into a larger space. In anotherapplication, the movement of the mobile device in real space allows auser to control the multi-dimensional movements and views of virtualobjects and/or virtual space.

[0019] While conventional input techniques are hindered by theirtwo-dimensional approach, the present invention permits input inmulti-dimensional space by detecting the user's physical movement of themobile device and mapping said movements to display-altering commands tomodify the view of the displayed data set, virtual object, and/orvirtual space. Thus, a user's movement of a mobile device, in one, two,three, and/or more degrees of freedom, may be correlated to the movementof a data set, visual objects, and/or virtual space in one, two, three,or more dimensions. That is, movements or gestures in many degrees offreedom may be translated to many dimensions in a data set and/oroperations over the data set. For purposes of this description, the term“gesture” is defined as limb and/or bodily motion intended to conveyinformation.

[0020]FIG. 1A illustrates a two-dimensional text data file 102. In afirst embodiment of the present invention, FIG. 1B illustrates how thedisplay screen of a mobile computing device 104 may serve as a virtualwindow to the larger data file 102 and display a portion of said datafile 106 with the mobile device at a first position.

[0021] According to one implementation, moving the mobile device left,right, up, or down may result in corresponding movements in the view ofthe document, data set, and/or visual object in the virtual space.

[0022]FIG. 1C illustrates the portion of the data 108 from the largerdata file 102 of FIG. 1A that may be displayed on the screen of themobile device 104 when the mobile device 104 is physically moved to asecond position. FIG. 1D illustrates yet a third view of the data on thedisplay screen 110 of the mobile device 104 when the mobile device 104is moved to a third position.

[0023] In various embodiments, the motions or gestures illustrated inFIGS. 1A through 1C may be along a two-dimensional plane orthree-dimensional space.

[0024] Note that the mobile device may display a reduced, unchanged, orenlarged version of the larger virtual space containing the data set.For instance, in FIG. 1E, the data displayed on the screen 112 of themobile device 104 is larger than that displayed in FIGS. 1B, 1C, and 1D.

[0025]FIGS. 2A, 2B, and 2C illustrate another embodiment of the presentinvention. When the user desires to scroll right or left to viewdifferent portions of a large data set, this may be accomplished byrotating the device about a substantially vertical axis. FIG. 2Aillustrates a mobile device 202 a at a first position displaying aportion of a data set 204 comprising a number list in increasing order.FIG. 2B illustrates how the data set in FIG. 2A may scroll right,thereby displaying higher numbers in the list 206, when the mobiledevice 202b is placed at a second position. This may be achieved byrotating the device clockwise about its vertical axis. Similarly, FIG.2C illustrates how the data set in FIG. 2A may scroll left, displayinglower numbers in the list 208, by placing the mobile device 202 c at athird position. This may be accomplished by rotating the mobile devicecounterclockwise about its vertical axis.

[0026]FIGS. 3A, 3B, and 3C illustrate yet another embodiment of thepresent invention where a user may scroll up or down to view a largedata set. When a user desires to scroll up or down to view a large dataset, this may be accomplished by rotating the device about asubstantially horizontal axis. FIG. 3A illustrates a mobile device 302 aat a first position displaying a portion of a data set 304 comprising anumber list in increasing order. FIG. 3B illustrates how the data set inFIG. 3A may scroll up, displaying lower numbers in the list 306, whenthe mobile device 302 b is moved to from the first to a second position.This may be result when the top edge of the device is tilted forward orrotated about its horizontal axis. FIG. 3C illustrates how the data setin FIG. 3A may scroll down, displaying higher numbers in the list 308,when the mobile device 302 c is moved from the first position to a thirdposition. This may be accomplished by tilting the top edge of the devicebackwards, thereby rotating the device about its horizontal axis.

[0027] The motions of the mobile devices describe with reference toFIGS. 2A-C and 3A-C may be relative, as measured versus on a priorposition, or absolute, as measured versus some fixed reference(s).

[0028] In various embodiments, the scrolling functions described withreference FIGS. 2A-C and 3A-C may be activated or deactivated by theuser through a gating mechanism or other means. Thus, the view of thedata set would not change unless the user activated the gesture-based ormotion-based feature.

[0029] The angle and/or speed of rotation may provide additionalinformation. For example, in one embodiment, the angle of rotationdetermines the speed at which the data scrolls on the display screen.For example, a greater angle may correspond to faster scrolling of thedata set.

[0030] Additionally, it must be understood that the present inventionmay be practiced by utilizing different axes and motions. The effectthat a gesture or motion has on the data or virtual environment may beconfigured according to the desired implementation. In one embodiment,the user may configure or map particular gestures or motions to adesired display-controlling command.

[0031] The intuitive interface of the present invention may also beemployed to display and move virtual objects, or other datarepresentations, in a mult-idimensional virtual space.

[0032]FIG. 4 illustrates how, in one implementation of the presentinvention, a three-dimensional virtual object may be displayed on thescreen of a mobile device. With the mobile device 404 a at a firstposition, the screen may display a first view of a virtual object 406.Physically moving the mobile device 404 b to a second position may causea second view of the virtual object 408 to be displayed. The viewdisplayed when the mobile device 404 b is at a second position maycorrespond to the view of the object which may be observed if the userhad changed his point of view. Further moving the mobile device 404 c toa third position may cause a third view of the virtual object 410 to bedisplayed.

[0033] According to another aspect of the present invention, shown inFIG. 5, the mobile device may be moved from a first position 502 a to asecond position 502 b to zoom in, or enlarge, the object displayed 504and 506 on the screen. In one embodiment, a gesture of moving the mobiledevice along an axis perpendicular to the display screen causes thevirtual space displayed on the screen to zoom-in when the motion is infirst direction along the axis, and to zoom out when the motion is inthe other direction along the axis.

[0034] From the examples shown in FIG. 1 through 5, a person of ordinaryskill in the art will appreciate that intuitive movements or gestures,in multiple degrees of freedom, may be mapped to correspond to movementsof the a data set, virtual object, and/or virtual space displayed on ascreen. Additionally, the motion of the mobile device may also be mappedto correspond to any other kind of command or function, such as turningthe device On or Off for instance.

[0035] An effective human-computer interface based on the movement ofthe mobile device may require that small movements be damped out.Otherwise, a user may become frustrated by the bouncing of the data,virtual data, and/or objects displayed resulting from every smalltwitches of the mobile device. The sensitivity of the interface may betuned based on the intended application.

[0036] According to one implementation, a user may select when theintuitive motion-based interface of the present invention is active.Various means to activate and deactivate the interface may be employed.In various embodiments, a button, a thumb switch, a hand pressureswitch, speech command recognition, stylus activated command, a touchscreen activated command, computer vision-based facial or hand gesturerecognition, and/or camera viewing of, or physical contact with,external objects may be employed for this purpose. A person of ordinaryskill in the art will recognize that this is a non-exhaustive list andthat other means of accomplishing this gating, or activation anddeactivation, function are possible and encompassed by this invention.

[0037] In various embodiments, the gating function may be accomplishedby moving the mobile device in a predetermined manner. For instance, inone embodiment, tilting the mobile device horizontally may activategesture recognition function while tilting it vertically may deactivategesture recognition function.

[0038] This invention may be practiced by detecting either the relativeor absolute motion of the mobile device. The relative motion of themobile device is that which is measured against a prior position of themobile device. The absolute motion of the mobile device is that which ismeasured against a unique (fixed) physical location. Either a relativeor absolute motion or gesture of the mobile device in real space may betranslated into either a relative or absolute motion of the virtualspace displayed on the mobile device as indicated below. Specifically, arelative motion in real space may be translated to a relative and/orabsolute motion and/or operation of a data set. Similarly, an absolutemotion in real space may be translated to a relative and/or absolutemotion and/or operation of a data set.

[0039] A person of ordinary skill in these arts will recognize that manydifferent combinations of gestures or motions may have a differenteffect on the data set, virtual object, or virtual environment displayedon the screen of the mobile device.

[0040] According to one embodiment, illustrated in FIGS. 2A-C and 3A-C,a user may tilt the mobile device a certain amount along a first axis tocause a data set to scroll either left, right, up, or down, until thetilt is stopped. The speed at which the data scrolls may be determinedby the tilt angle relative to a neutral position.

[0041] In another implementation, a user my depress a gesture gatingbutton and move the mobile device slightly forward to move the user froma first virtual chat room to a second virtual chat room at a constantspeed. The gesture gating button may be released to stop at the secondvirtual chat room.

[0042] In other embodiments, mixed mode operation is also possible. Forexample a user may move the mobile device to an absolute position,relative to some fixed point, to view a specific location on atwo-dimensional map displayed on the screen. The user may then employrelative motion, by moving the device in or out for instance, to viewchanges in the map location over time. Moving the device inwards oroutwards may advance or retreat the view of the map location accordingto time.

[0043] Additionally, the present invention may be practiced along withother forms of inputs such as a touch screen or stylus. For example, inone embodiment, the user may draw a virtual figure by using a stylus todraw on the display screen while moving the mobile device inmulti-dimensional space to move around the canvas. In anotherapplication, the user may move the mobile device in three-dimensionalspace to draw a three-dimensional virtual object with the stylus.

[0044] In another embodiment, the user may select a virtual object onthe display and then move it around the virtual space by moving themobile device in real space.

[0045] In yet another embodiment, the present invention may allow a userto operate virtual controls on a virtual control board by moving themobile device in real space to display different parts of the controlboard and selecting a desired virtual control by using another form ofinput such as a touch screen, stylus, or voice command.

[0046] By correlating intuitive gestures or motions to certain commands,the mobile device may serve as a virtual tool with differentapplications. For example, the mobile device may serve as a virtualsculpting tool, such as a chisel, where the motion of the mobile devicein real space may correspond to the chiseling of a virtual block ofstone displayed on the mobile device's screen. The sculptor may use oneor more gating switches or buttons to activate the chiseling functionand/or to zoom and move around the virtual block of stone. Theacceleration of the device in any particular direction may serve as anindication of force to the virtual space to remove more or less materialfrom the virtual block of stone.

[0047] Similarly, the present invention may permit a mobile device toserve as a trowel for molding clay in virtual space. The motion of themobile device in three-dimensional space may serve to indicate how apiece of virtual clay may be shaped. Like the sculpting tool describedabove, the user may also use gestures and motion to move around thevirtual space and acceleration to indicate force.

[0048] Detection of the relative and/or absolute motion of the mobiledevice may be achieved in a number of ways. While a few methods ofmotion detection are disclosed herein for purposes of illustration, itshould be recognized that many other means of achieving relative andabsolute motion detection are available and the present invention is notlimited to those means disclosed herein.

[0049] According to one embodiment, one or more accelerometer may beemployed to detect movements or gestures. In one implementation, oneaccelerometer may be employed for each axis of movement that one desiresto detect.

[0050] In one implementation, a single accelerometer mounted on a firstaxis to detect movement along that axis to detect relative movement,absolute acceleration, and/or absolute movement by integrating theacceleration. For instance, in FIG. 5, a single accelerometer may bemounted on the device 502 to sense motion along an axis perpendicular tothe display screen to enable zooming in and zooming out the virtualspace 504 and 506.

[0051] In another embodiment, a first accelerometer may be mounted on afirst axis and a second accelerometer may be mounted on a second axis todetect movement along a two-dimensional plane defined by the first andsecond axes and/or rotation along said axes. The accelerometers may beemployed to detect relative movements or gestures, absoluteacceleration, or absolute movement by integrating the acceleration alongthe first and second axes. For instance, the mobile device illustratedin FIGS. 1A-E may comprise two accelerometers which may detect thedevice's motion along a plane. Thus, the view of the data set or virtualspace on the device's screen may be modified based on the motion sensedby the accelerometers.

[0052] In a third embodiment, movements or gestures in three-dimensionalspace may be detected by employing three accelerometers, eachaccelerometer detecting motion on a different axis. By correlating eachof the three axes to the orientation of the mobile device, the tilt,pitch, and yaw of the device may be detected. For instance, relativegestures or movements in six degrees of freedom, absolute accelerationin six degrees of freedom, and/or absolute movement in six degrees offreedom by integrating the acceleration may be detected. The mobiledevice shown in FIG. 4, for example, may comprise three accelerometerson three different axes to detect motion in six degrees of freedom andenable changing the view of the virtual space displayed based on thesensed motion.

[0053] Note that the accelerometers, and/or other motion sensing means,may be mounted inside the mobile device or be separate from the mobiledevice. That is, so long as motion information is conveyed to thedisplay changing means, the motion or gesture detecting means may beremote from the mobile device.

[0054] Other means for detecting the motion of a mobile device includeultrasonic means and/or magnetic means to provide relative and/orabsolute movement, location, and or orientation of the device. Saidinformation may then be employed to modify or alter the view of the dataset, object, or virtual space displayed on the screen of the virtualdevice.

[0055] In one implementation, ultrasonic means may include oneultrasonic source or clicker in combination with two ultrasonic sensors,such as microphones, to provide the relative and/or absolute location ofthe mobile device along two dimensions such as a plane. Similarly, oneultrasonic source in combination with three sensors may be employed toprovide the relative and/or absolute location of a mobile device.Typically, the ultrasonic source provides a signal which, when receivedby the ultrasonic sensors, may be used to calculate the position of themobile device.

[0056] In another embodiment, two ultrasonic sources and two sensors maybe configured to provide the location plus pitch or yaw of the mobiledevice. Similarly, utilizing two ultrasonic sources and three sensors amobile device's location plus pitch and yaw may be determined. Like theexamples before, the signals provided by the ultrasonic sources andreceived by the sensors may be used to calculate the relative and/orabsolute position of the mobile device. In one implementation this maybe done by measuring the different time of reception by each ultrasonicsensors and using this information to determine the position of themobile device.

[0057] In yet another embodiment, three ultrasonic sources incombination with two sensors may be configured to provide the locationalong a two-dimensional plane, pitch, and roll of a mobile device. Threeultrasonic sources and three sensors may also be arranged or configuredto provide the three-dimensional location, pitch, yaw, and roll of amobile device.

[0058] A magnetic dipole source may be similarly employed to provide therelative or absolute location and/or orientation of a mobile device. Forinstance, the combination of one magnetic dipole source and two sensorsmay be configured to provide the location in a two-dimensional plane andpitch or yaw of a mobile device. Three sensors and one magnetic dipolesource may be configured to provide the absolute and/or relativethree-dimensional location, pitch, and roll of the mobile device.

[0059] In another embodiment, two magnetic dipoles and two sensors maybe configured to provide the location, along a two-dimensional plane,and the pitch and roll of a mobile device. Three sensors and twomagnetic dipoles may also be configured to provide the relative and/orabsolute three-dimensional location, pitch, yaw, roll of a mobiledevice.

[0060] The means for detecting motion, including ultrasonic clickers andmagnetic dipole sources, may be configured to track the changes intwo-dimensional or three-dimensional space, including locations andorientation of the mobile device, over time to provide relativemovements, and/or relative or absolute accelerations. Note that witheither the ultrasonic or magnetic dipole system, the sources and sensorsmay be configured in various ways known to those of ordinary skill inthe art. For instance the sources maybe mounted on the mobile devicewhile the sensors may be external to the device. In another embodiment,the sensors are coupled to the mobile device while the sources areexternal to or separate from the device.

[0061] Yet another means of obtaining the three-dimensional, six degreesof freedom, location and/or orientation of a mobile device is visualtracking using a calibrated computer vision system.

[0062] In one implementation, illustrated in FIG. 6, one or moreexternal cameras 602 may determine the three-dimensional location andorientation of a mobile device 604 a and 604 b based on three or moremarkings 610, 612, and 614 on the mobile device 604 a and 604 b. Thecamera(s) 602 may provide images of the mobile device including saidmarkings. The images may then be processed, by identifying said markingsto provide the relative and/or absolute location and orientation of themobile device. Using said information, the mobile device may be capableof displaying different views of the virtual space or object. Forinstance, in FIG. 6, moving the mobile device from a first position 604a to a second position 604 b may cause the virtual space to change froma first view 606 to second view 608. In one implementation, the secondview of the virtual space or object may correspond to the view as seenby an observer who moves from the first position to the second position.

[0063] According to a second implementation, illustrated in FIG. 7, themobile device 702 may include a camera 704 which, by detecting thelocation of external reference points 710, 712, and 714, may be used todetermine the absolute or relative location and orientation of themobile device 704. Thus, the mobile device may display a first view 706when it is at a first spatial position 702 a and a second view 708 whenit is at a second spatial position 702 b. In one embodiment, therelative motion of the device may be determined by optical flow methods,identifying the change in visually perceived objects for instance. Inanother embodiment, the absolute motion may be determined from thestructure of known, visually perceived, reference objects.

[0064] While a few position, gestures, and motion detection means havebeen described, many other means, including infra-red emitter detectorsand global positioning systems, may be employed without deviating fromthe present invention.

[0065] In one embodiment of the invention, the motion detection meansand mobile device must be within 1 mile of each other. In a secondembodiment, the motion detection system and the mobile device must bewithin 100 feet of each other. In a third embodiment, the motiondetection system must be physically coupled to the mobile device.

[0066] Additionally, all or part of this invention may be practiced byhardware components, programmable devices, software, and/or integratedcircuits.

[0067] While the invention has been described and illustrated in detail,it is to be clearly understood that this is intended by way ofillustration and example only and is not to be taken by way oflimitation, the spirit and scope of this invention being limited only bythe terms of the following claims.

What is claimed is:
 1. A method comprising: detecting the motion of amobile device; and modifying the display of the mobile device based onthe detected motion of the mobile device.
 2. The method of claim 1wherein detecting the motion of a mobile device includes detecting themotion in one or more spatial dimensions.
 3. The method of claim 1wherein detecting the motion of a mobile device includes: detecting themotion of the device in multi-dimensional space; and measuring the timeof the motion.
 4. The method of claim 1 wherein the relative motion ofthe mobile device is detected.
 5. The method of claim 1 wherein theabsolute motion of the mobile device is detected.
 6. The method of claim1 wherein modifying the display is based on a predetermined relationshipbetween the motion and one or more display altering commands.
 7. Themethod of claim 1 further comprising: correlating the motion of themobile device to one or more commands.
 8. The method of claim 7 whereinthe one or more commands include display altering instructions.
 9. Themethod of claim 1 wherein tilting the mobile device along its long axiscauses a displayed document to scroll until the tilt is stopped.
 10. Themethod of claim 1 wherein moving the mobile device along an axisperpendicular to the display screen causes the displayed data to zoom inif the motion is in a first direction and zoom out if the motion is in asecond direction.
 11. The method of claim 1 wherein moving the mobiledevice from a first position in space to a second position is spacecauses the view of a displayed object to change from a first position toa second position.
 12. A method comprising: detecting the gesture-basedmotion of a mobile device; and modifying the display of the mobiledevice based on the detected motion of the mobile device.
 13. The methodof claim 12 wherein the relative gesture-based motion of the mobiledevice is detected.
 14. The method of claim 12 wherein the absolutegesture-based motion of the mobile device is detected.
 15. A devicecomprising: a processing unit to receive input signals and generateoutput signals; a display screen, coupled to the processing unit, todisplay information according to signals received from the processingunit; and a motion detection system communicatively coupled to theprocessing unit, to detect the motion of the device and providecorresponding signals to the processing unit.
 16. The device of claim 15wherein the processing unit receives input signals from the motiondetection system and generates display altering output signalscorresponding to the input signals from the motion detection system. 17.The device of claim 15 wherein what is displayed on the display screenchanges according to a predetermined relationship between the motion ofthe device and the corresponding effect on the view of what is displayedon the screen.
 18. The device of claim 15 wherein the motion detectionsystem detects the gesture-based motion of the mobile device.
 19. Thedevice of claim 15 wherein the motion detection system includes one ormore accelerometers configured to detect the motion of the device in oneor more spatial dimensions.
 20. The device of claim 15 wherein themotion detection system includes one or more ultrasonic sensorsconfigured to detect the motion of the device in one or more spatialdimensions.
 21. The device of claim 15 wherein the motion detectionsystem includes one or more magnetic sensors configured to detect themotion of the device in one or more spatial dimensions.
 22. The deviceof claim 15 wherein the motion detection system includes an opticaldetection apparatus coupled to the device to detect multiple externalreferences from a first position and from a second position to determinethe device's motion.
 23. The device of claim 15 wherein the motiondetection system is physically detached from the mobile device.
 24. Thedevice of claim 15 wherein the motion detection system includes multiplereference markers on the device and an optical detection apparatusseparate from the device to detect the multiple reference markers whenthe device is at a first position and at a second position therebydetermining the device's motion.
 25. A system comprising: means fordetecting the motion of a mobile device; and means for modifying what isdisplayed on the screen of the mobile device based on the detectedmotion of the mobile device.
 26. The system of claim 25 furthercomprising means for correlating the motion of the mobile device to oneor more display altering instructions.
 27. The system of claim 25wherein what is displayed on the display screen changes according to apredetermined relationship between the motion of the mobile device andcorresponding effect on the view of what is displayed on the screen. 28.A machine-readable medium comprising at least one instruction tocorrelate motion in real space to motion in virtual space, which whenexecuted by a processor, causes the processor to perform operationscomprising: detecting the motion of a mobile device; and correlating themotion of the mobile device to a one or more display altering commands.29. The machine-readable medium as recited by claim 28 furthercomprising: modifying the display of the mobile device based on the oneor more display altering commands.
 30. The machine-readable medium asrecited by claim 28 wherein detecting the motion of a mobile deviceincludes detecting gesture-based motions of the mobile device.